1. Field of the Invention
This invention relates to a low-voltage switchgear assembly or switchboard or switching station or distribution switchboard for distribution of electrical energy. The low-voltage switchgear assembly contains switching equipment or equipment groups located in plug-in units, containing equipment such as power circuit breakers, motor circuit breakers, motor control centers or similar devices. The plug-in units have guides in the switchgear cabinet and are provided with a cabinet-shaped metal housing and at least one switchgear cabinet door. At least the electrical connection from the bus bars to the switching equipment is of the plug-in type, whereby the guide fittings are stamped and the plug-in units have guide edges which run parallel to the plane of the floor, whereby moreover the bus bars are field bus bars which are connected to main bus bars.
2. Background Information
In power distribution applications, low-voltage switchgear assembles consisting of switching equipment or groups of equipment located in switchgear cabinets, also called motor control centers (MCCs) or energy control centers, have long been successfully used for the protection of equipment and motors.
The output and distribution of the electrical energy is achieved by means of common busbars or interchangeable equipment units or groups of equipment, whereby these groups of equipment contain switching and protection components, and are engaged with the busbars by means of plug-in contacts.
At least some of the equipment groups on distribution boards of this type are of the plug-in type, whereby at least the load current taps are realized in the form of plug-in contacts which are engaged on the busbars.
The load current and the control current connections or similar connections can be realized either as plug-in type connections or can be hard-wired.
The switching and protection components can be power circuit breakers, motor circuit breakers, contactors and combinations of these components, such as a reversing star-delta combination or a similar combination.
German Patent No. A1 42 10 679 describes a similar power distribution board which has cross struts which run parallel to the insertion direction, which cross struts have guide means for the plug-in units, whereby the guide means are realized in the form of graduated or step-shaped or Z-shaped guide extensions and are stamped in one piece out of the material, which material was used to manufacture the guide means.
These guide means, of course, are relatively economical, but if the field bus bar system is designed to be a compact unit, cross struts are also necessary for guidance. European Patent No. 0 186 556 illustrates and describes a field bus bar system with a bus duct, whereby the plug-in units are located on the sides. The bus system forms a compact unit which can be installed in any desired metal switchgear cabinet. However there is no guidance of the plug-in units in the sense of the present invention.
WO 93/18564 also describes a power distribution board which has guide slots located on wall elements, although the distribution board in question is complex and expensive to construct.